This invention relates to timing the administration of insulin and various fuels (carbohydrates, proteins, and fats) to individuals whose fuel processing (i.e., oxidation, storage, and conversion to other substrates) capabilities are chronically abnormal (e.g., diabetic subjects) or acutely disrupted (e.g., accidentally or surgically traumatized patients).
The normal fuel processing capabilities of the body, such as of the liver and other tissues, e.g., muscle, can be disrupted by disease (e.g., diabetes) and by trauma (accidental or surgical).
(Insulin is often administered in large quantities to diabetic subjects, surgical patients or accident (especially burn) victims in attempts to restore normal fuel processing capabilities and to prevent the breakdown of muscle protein. Since massive doses of insulin lower blood sugar levels, glucose may also be infused.
Established treatment programs for diabetic patients administre insulin to control blood glucose concentrations. Insulin infusion patterns based directly on measured blood glucose levels are disclosed in Aisenberg et al., U.S. Pat. No. 3,387,339; Klein, U.S. Pat. No. 4,206,755; Edelman, U.S. Pat. No. 4,073,292; and Chem. Abstracts, 92:135345m. Insulin infusion patterns based on projected blood glucose levels and expected changes in blood glucose levels, calculated using measured blood glucose levels, are disclosed in Ablisser et al., U.S. Pat. No. 4,245,634; Schindler et al, U.S. Pat. No. 4,253,456; Clemens, U.S. Pat. No. 4,151,845; Clemens et al, U.S. Pat. No. 4,055,175; and Chem. Abstracts, 89:39926u. In programs of the above types, both the amount of insulin infused and the duration of the infusion are dependent on measured glucose concentrations. That is, when measured glucose concentration and/or projected concentrations arise to a certain perscribed limit, insulin is administered. Insulin infusion then continues until such glucose concentrations approach or fall below a certain level.
In addition to these patterns of insulin infusion based on concurrently-measured glucose levels, insulin-administering devices have been developed which can infuse insulin according to a predetermined profile of the patient's insulin requirements. For example, Franetzki et al, U.S. Pat. No. 4,482,872, discloses such a device wherein a base rate of insulin is continuously infused and the predetermined program (stored in a microprocessor), which typically administers a larger amount (pulse) of insulin, can be called up by the patient when needed. Haerten et al, U.S. Pat. No. 4,077,405, likewise discloses a device which can administer pulses of medication (e.g., insulin) over a constant baseline in response to pre-programmed or manually-controlled signals. These devices administer insulin in patterns which, like the above-mentioned methods which respond to concurrently-measured glucose concentrations, are a function of and are designed to directly control the actual concentration of glucose in the blood stream.